1. Field of the Invention
The invention relates to a method for building a radial tire utilizing the following steps: Building a belt package of at least two, in particular, automatically spliced belt plies on a segmented belt build-up drum having a cylindrical outside circumference; Building a carcass tube having an airtight inner layer, at least one carcass ply and two bead cores with core profiles on a separate building drum; Transferring the carcass tube to a further segmented building drum to which bellows supports moveable in the axial direction or core clamping devices with inflatable bellows or deflector devices are connected laterally; and Transferring the belt package to the further building drum and positioning the same over the carcass tube.
The invention further relates to a device for building a radial tire with the following features: A segmented belt build-up drum having a cylindrical outside circumference; A separate building drum for building a carcass tube from at least one airtight inner layer, a carcass ply and two bead cores with core profiles; A transfer device for transferring the belt package from the belt build-up drum to a further segmented building drum; On which the carcass tube and the finished belt package can be joined; Whereby axially moveable bellows supports or core clamping devices are arranged at the side of the further building drum.
2. Discussion of Background Information
In the conventional manufacture of radial tires for automobiles, the contouring of the steel belt comprising at least two belt plies generally does not occur until the vulcanization of the tire by the molding of the green-cover built on cylindrical building drums by means of a bellows inflated in the interior of the green-cover inserted into the tire mold. The belt and the tread are thereby given their final contour, whereby the elevation or extension of the belt is larger in the zenith of the tire than in the shoulder areas. A non-uniform expansion of the material in the tire, in particular, the strength supports in the belt plies and the winding bandage, occurs in this manner across the cross section of the tire. This non-uniform expansion results in a material displacement of the belt plies relative to the components surrounding them, in particular, a change in the angle of the strength supports in the belt plies over the cross section of the tire and an inward contraction of the belt edges radially inside the bandage applied to the belt and an unequal distribution of tension of the strength supports located above the belt.
Furthermore, methods and devices are known for building a green-cover on a segmented stable core, the external surface of which corresponds at least essentially to the inner surface of the tire to be formed. In this context, reference is made, e.g., to U.S. Pat. No. 5,616,209. Most of the components of the tire are thereby produced from strip-shaped rubber mixtures and from textile or metallic threads by application by means of special devices. The tire is heated together with the stable core and therefore without bellows, so no residual elevation occurs either during the vulcanization. These methods are technically very complex and economical only to a limited extent.
In the production of radial tires for trucks, it is known to apply the belt to a building drum already contoured according to the desired contour of the belt package in a conventional manner. However, with this building method the belt plies can be spliced only manually, since the splice of the overlapping end sections of each belt ply cannot be supported over the entire width of the building drum.